A novel modified glassy carbon electrode（GCE）with Schiff-base copper（Ⅱ） complex/multi-wall carbon nanotube was fabricated using a cyclic voltammetric method in phosphate buffer solution.The Ip of ascorbic acid at Schiff-base copper（Ⅱ） complex/multi-wall carbon nanotube modified electrode was proportional to the square root of scan rate suggesting a diffusion controlled process.This modified electrode exhibited electrocatalytic response to the oxidation of ascorbic acid.The results of line sweep voltammetry showed that the peak current was proportional to the concentration of ascorbic acid in the range of 0.1-1.1 mmol·L-1.The sensitivity is 29.709 nA/（μmol·L-1） and the detection limit is 0.303 μmol·L-1.